anchor chain change out

[mnh]

Hi all,
It's time to change out my 300 ft of (really ) old anchor chain. I have a couple of questions:
1) Is there any advantage to stainless chain? Cost difference?

2) I'll cut down the 300 ft of chain, to 200 ft., with a nylon rode spliced in..
What would you recommend for nylon rode diameter size, and would 75 ft. about do it?

The boat is 30,000 lbs loaded, 45 ft long. We sail the East Coast of the US,
and The Bahamas are about as far as we intend to go. 20 ft. depth is about the limit for our type of anchoring.

Thanks much in advance for your replies!
mnh